Hazel Stewart told detectives she wanted to take the secret she had carried for almost 20 years to the grave for the sake of her children and second husband, police interview tapes played to Coleraine Crown Court in Co Derry revealed.

The 47-year-old mother of two denies being part of a joint enterprise with her then lover Colin Howell to poison her policeman husband Trevor Buchanan (32) and Howell's wife Lesley (31) in May 1991 -- crimes police concluded were suicide until Howell confessed 18 years later.

But she has admitted knowing about the murders on the north coast and going along with the deception that it was a suicide pact.

As her trial entered its third week, the packed courtroom fell silent as the first of 15 tapes Ms Stewart gave to police following her arrest in January 2009 -- hours after Howell confessed -- were played to the jury.

She told the investigating officers: "I was so scared and I have lived every day of my life since that happened wanting to die. . . I would have taken it to my grave because of my children and my family."

Throughout the questioning Ms Stewart, of Ballystrone Road, Macosquin, Coleraine, insisted that the idea was Howell's and that he forced her to go along with it. She also expressed fear that her lover might have killed her if she did not co-operate.

Ms Stewart sat impassively as the court was played three hours of taped interviews.

"My personality is soft and weak. . . and he had full control over me," she said of her relationship with Howell. "That's no excuse. It was just he had full control and he kept saying that this is the only way. . ."

Ms Stewart added: "He didn't get my approval and I would not agree with him. . . He is. . . very controlling. He gets his own way, in one shape or form.

Devious

"Whether he fools you, or cons you, whatever, he will get you. If he wants something he will get it. As the relationship went on, there was other things that. . . scared me. He's just devious, and I mean that."

Dentist Howell, a father of 10, from Glebe Road, Castlerock, Co Derry, is serving a 21-year jail sentence after pleading guilty to the two murders at Belfast Crown Court last November.

Last week, Howell spent four days in the witness box testifying against his former lover. He claimed he gave her tablets to sedate her policeman husband before gassing him with carbon monoxide fumes as he slept -- the same way he murdered his wife earlier at their home.

He then drove the two bodies to the neighbouring seaside town of Castlerock, where he stage-managed the apparent suicide.

In the four tapes played to the court, Ms Stewart also told police:

Howell wanted to claim parental rights on an unborn child while she was still with Pc Buchanan. She ultimately aborted the child.

Howell told her to wait in another room while he went and killed her husband. She never saw the actual murder.